1. Field of the Invention
The present invention relates to a method of cleaning actuators of metered dose dispensers used to dispense pharmaceutical compositions. The invention also relates to a composition to be used in cleaning actuators of metered dose dispensers.
2. Description of the Related Art
Metered dose spray devices are presently used to administer many different medications to the mouth and lungs, for example, asthma medication and nitroglycerin for treatment of heart disease. A typical metered dose spray device includes a container, for example, a can, for containing a solution or suspension of medication, a metering valve, and an actuator. The can will contain the medication to be dispensed, possibly a solvent for the medication, and a propellant. The propellant is a substance having a low boiling point and high vapor pressure, so that as liquid is dispensed from the container the propellant evaporates, thereby maintaining a constant pressure within the can. Actuation of the metering valve causes the metering chamber within the valve to close with respect to the can's interior, and open with respect to the mouthpiece (the structure of the actuator to be positioned in communication with the user's mouth). Propellant within the metering chamber will evaporate due to the sudden decrease in pressure when the valve is actuated, propelling the medication into the user's mouth.
After repeated use, the actuator can become clogged with the medication being dispensed. This can interfere with proper dosing and delivery of the medication. It is desirable, therefore, to provide a method of cleaning the actuator on a regular basis to resist clogging and assure delivery of the desired amount of medication.